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Node-RED for IoT

Node-RED for IoT

Introduction

Your ESP32 publishes MQTT messages — now what? Node-RED is a visual flow editor that runs on a Raspberry Pi, laptop, or server. You drag nodes (MQTT in, JSON parse, dashboard gauge, HTTP post) and wire them without recompiling firmware.

In HBO-ICT IoT projects, Node-RED is the usual glue between devices, databases, and dashboards. It pairs with MQTT and IoT messaging and Connectivity architecture.

What Node-RED does

1
2
3
[ MQTT in ] → [ JSON ] → [ function ] → [ dashboard chart ]
                ↓
           [ InfluxDB / file / email ]
Piece Role
Flow One canvas of connected nodes
Inject Manual or timed test trigger
MQTT nodes Subscribe/publish to broker
Function Small JavaScript snippet on message
Dashboard Buttons and charts in browser

In plain terms

Node-RED is Lego for data pipes. Firmware sends one JSON blob; Node-RED splits, filters, and shows it — without flashing the MCU again.

Typical lab setup

  1. Mosquitto broker on Pi or PC (1883)
  2. Node-RED installed (node-red-start)
  3. MCU publishes lab/device1/temperature
  4. Flow subscribes, converts payload, updates UI
  5. Optional: flow publishes lab/device1/cmd/led back to device

Broker address — use static IP or hostname everyone agrees on.

Security (do not skip in production)

  • Change default editor port protection — set admin password
  • Use TLS on MQTT when not on isolated lab VLAN
  • Do not expose Node-RED editor to the public internet without hardening

Official guides: Securing Node-RED

Custom nodes (advanced)

Teams sometimes package reusable flows as custom nodes — same idea as firmware modules, but in JavaScript.

Videos — other ways to learn

Fundamentals (part 1)

Intro to Node-RED: Part 1 Fundamentals

MQTT publish and subscribe in Node-RED

MQTT Publish and Subscribe Using Node Red

End-to-end ESP8266 demo

[DEMO] ESP8266 and Node-RED with MQTT

Relevant topics

Starting points

  1. Install Node-RED on a Pi; open editor at http://<pi-ip>:1880.
  2. Drag MQTT In + Debug; subscribe to # and see traffic.
  3. Publish test message with mosquitto_pub; watch Debug panel.
  4. Add Dashboard gauge — show one sensor field.

Focus points

  • Topic naming — match MCU firmware exactly (case sensitive).
  • JSON — invalid payload breaks Function node; validate in Debug first.
  • One flow per concern — sensor ingest vs command outbound.
  • Version flows — export JSON to Git with your project.

Key points

  • Node-RED connects MQTT devices to dashboards and backends without MCU changes.
  • Runs on Pi/PC/server next to your MQTT broker.
  • Learn MQTT first, then wire flows; secure before leaving the lab network.